Systemic lupus erythematosus (SLE) is an autoimmune disease characterized by heterogeneous clinical manifestations involving virtually the entire body. The pain in SLE can have different causes. The SLE classification criteria include mainly the musculoskeletal manifestations of pain, which are commonly reported as initial symptoms of SLE, such as arthralgia, arthritis and/or myalgia. Chronic widespread pain, which is typical of fibromyalgia (FM), is frequently associated with SLE. The aim of this review is to describe widespread pain and fatigue in SLE, and the association of SLE and FM. Although secondary FM is not correlated with the disease activity, it may interfere with the daily activities of SLE patients. Therefore it is necessary to identify its symptoms and treat them promptly to improve the quality of life of patients. In conclusion, it is essential to identify the origin of pain in SLE in order to avoid dangerous over-treatment in patients with co-existing widespread pain and FM.